1. Field of the Invention
This invention relates to backwater valve structures for sewage and drainage conduits and also to sewer cleanout devices.
2. Description of the Prior Art
It is highly desirable and usually mandatory, in the plumbing art, that backwater valves, often deeply buried, be readily accessible for replacement and maintenance. It is also highly desirable, for reasons of cost efficiency and labor efficiency, that a minimum of structure be involved for both backwater valves and for sewer and drainage clean-outs.
Backwater valves are required by law in many municipalities for a variety of reasons. It is becoming increasingly common for cities, municipalities, and sewer districts to specify the use of backwater valves on all installations so as to protect themselves from liability in cases where a clogged sewer line should back up in situations where backflow may be caused by maintenance workers during pressure flushing operations or for other reasons. All backwater valves, presently known, are accessible only by means of a masonry pit or a manhole, except for those within an arm's reach of ground level. As the depth of a drainage line or sewer line, the term herein used interchangeably, increases, especially in situations such as basement drainage applications, the cost of providing a masonry pit or manhole becomes increasingly costly, inconvenient, and often unsightly. Because of these difficulties, legal requirements are often not enforced.
In an attempt to overcome the problems associated with access to backwater valves, a device, shown in U.S. Pat. No. 2,718,238, issued to A. Simko, Sr., was invented. The Simko device utilizes a solid stem, defining a narrowed horizontal conduit complete with valve seat and flapper, which is receivable within a vertical sleeve intersecting with drainage inlet and outlet conduits. In this manner, the stem of the Simko device may be removed for maintenance or replacement of the entire valve system. The Simko invention, however, suffers from several serious flaws and therefore has not been adopted by the industry. Simko does not provide a valve seat about the entirety of the horizontal drainage pipe; constricts and obstructs the horizontal pipe, which is now against regulations; and is subject to displacement or partial displacement of the stem and entire valve system by backwater pressure. Further, clean-out capabilities are not present without complete removal of the backwater trap.